DIN EN 60671:2011-12

This standard lays down principles for testing I&C systems performing category A, B and C functions, per IEC 61226, during normal power operation and shutdown in order to check the functional availability, especially with regard to the detection of faults that could prevent the proper operation of the functions important to safety. It covers the possibility of testing at short intervals (or continuous surveillance), as well as periodic testing at longer intervals. It also establishes basic rules for the design and application of the test equipment and its interface with the systems important to safety. Further, the effect of any test equipment failure on the reliability of the I&C systems is considered. The various possible types of surveillance tests include - self-tests for I&C equipment; - tests of a group of equipment or components to confirm properties that support the safety function (continuity, power availability, etcetera); - tests based on information redundancy or comparison of control signatures (consistency checking for redundant sensors, CRC-checking, Checksum, etcetera); - periodic testing which is related to the correctness of functional behaviour of an I&C system. The dependability targets of any I&C system is reached using an appropriate combination of tests of the form indicated above. The extent of the I&C system to be tested is from the interface of the sensors with the process through to the actuation devices. It is applicable to the installed I&C systems as well as to temporary installations which are part of those I&C systems important to safety (for example, auxiliary equipment for commissioning tests and experiments). The responsible committee is Subcommittee UK 967.1 "Leittechnik für kerntechnische Anlagen" ("Instrumentation for nuclear facilities") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.